How is coconut oil made?

Coconut oil refers to a type of oil extracted from the white part of a mature coconut fruit referred to as the kernel. Coconut oil has a high saturated fat content that makes it resistant to rancidification. Therefore, the oil can last for up to six months at temperatures of 24oC without spoiling. There are two main methods used to extract coconut oil.

Dry Process

The first step of the dry process is the separation of the kernel from the shell of the coconut. The kernel is then dried. Drying of the kernel is accomplished through a variety of ways. For example, the kernel can be left to dry naturally in the sunlight for several days. Other methods of drying include heating the kernel in fire or a kiln. After the kernel is dried, it is referred to as the copra. After drying, oil is extracted from the copra through the use of solvents or pressing the copra. The process produces oil, high-fiber mash and high protein.

Wet Process

The wet process is used to extract coconut oil from the kernel as opposed to the copra. The kernel is pressed to produce a white emulsion of oil, water and proteins. The oil is then separated from the other components of the emulsion through a variety of methods. One of the methods used is prolonged boiling. However, the method is uneconomical and results in production of colored oil due to the presence of proteins and other contaminants.

Other methods of separating the oil from the emulsion include use of a centrifuge and use of pre-treatments such as solvents and acids. Hexane is the preferred solvent used for extraction of coconut oil and it produces 10% higher oil yield than when using a centrifuge. Centrifugation is the most commonly used method. Here, the emulsion extracted from pressing the kernel is put in different jars that are then placed in a centrifuge. The centrifuge then rotates at speeds in excess of 1000 rpm. The centrifugal force causes the different components of the emulsion to separate according to their density.

However, although the wet process is faster in extracting coconut oil and is a more viable option for commercial production, it produces 10-15% lower yield of coconut oil than th dry process. Moreover, the wet process can be capital intensive as it requires the installation of expensive equipment such as centrifuges. In addition to the method of extraction used the level of coconut oil produced and the quality of the oil can depend on age of the coconuts used in the process. Kernels from younger coconuts yield lower amounts of oil that is of a lower quality than the oil extracted from more mature coconuts.

Various methods are used to increase the shelf life of coconut oil. In dry processes, use of copra with a moisture content lower than 6% results in production of oil that has a moisture content of lower than 0.2%. The moisture content of the oil produced can also be lowered by heating the oil to a temperature of 130-150oC. Adding salt and citric acid to the oil also increases its shelf life.